Rudolph, A. J. (Department of Pediatrics, Baylor College of Medicine, Houston, Texas). Failure to tbrive in the perinatal period. Acta Paediatr Scand, Suppl. 319 55. Identiflcation of newborn nutritional inadequacy is one of the W o r areas in perinatal medicine where intervention can influence outcome. An infant's failure to thrive may be the d t of prenatal andor post-natal causes. Management of failure to thrive in the newborn infant must include identification of the problem, establishment of an efflcient therapeutic regimen and means of evaluating the morbidity which may occur. Key words: Failure to thriw, growth retadation, fetal and n e o d nulrition.